Yoshiyuki Sadamoto(貞本 義行,Sadamoto Yoshiyuki?, born January 29, 1962, in Tokuyama (now Shunan), Yamaguchi Prefecture, Japan) is a Japanese character designer, manga artist, and one of the founding members of the Gainax anime studio.

According to Yasuo Otsuka, who guided Sadamoto as a newcomer, there are only three people whom he regarded as more skillful than himself that he has met during his career. One of them is Yoshiyuki Sadamoto. The other two are Sadao Tsukioka who became a visual creator, and award-winning director Hayao Miyazaki. When Otsuka met the three men, he seems to have felt that he was taking off his hat to them at once. However, he thinks that only Miyazaki completely mastered a genuinely superior animation technique at present. He guesses, "A too excellent person might despair in the group work".[citation needed]

During an interview with Japanese Entertainment website Nihongogo done in 2013, it was revealed that Sadamoto is a stickler for details and wouldn't feel comfortable illustrating anything too unfamiliar with him. "In general, I don’t want to draw something that I have to study further in order to draw. For example, I could not draw a medical manga because it’s impossible for me to make a lie about medicine. Also things like Soccer and Baseball. I am unfamiliar with these worlds so it would be too difficult to show the actual plays." When asked about dream collaborations he revealed an interest in working with Robert Westall and Philip K. Dick but apologized "These are all deceased people, sorry."[1]